1977 Pontiac Trans Am – Factory Fresh, Part 1

Underhood - Exploring the minute details of a 213-mile '77 T/A

If you’ve ever viewed the spectacle of a modern manufacturing facility, you’ll understand the importance of an assembly line. By equipping line workers with the tools and training to complete a specific task, they quickly perform their portion as the partially assembled vehicle passes by on its way to the next line worker, who then performs a subsequent task.

Ensuring that workers perform their duties swiftly and nothing holds up the total process is the challenge of any assembly line. That means, for example, if using a fastener from a different supplier or routing wiring slightly differently was required to keep production flowing, it certainly wasn’t an issue as long as it didn’t compromise functionality or quality.

The reward for efficiency is directly reflected in the number of units produced, but pushing workers and equipment beyond their physical capacities can cause quality to suffer. No one knew this better than General Motors during the ’70s and ’80s.

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The atmosphere around the production facility in Norwood, Ohio, was hectic during the mid-’70s. As the only General Motors Assembly Division (GMAD) plant producing the F-body, and with the popularity of the Camaro and Firebird soaring — particularly that of the Trans Am—the plant was pressed beyond its intended capacity.

The average number of units produced during a single day in the ’76 model year was about 335. In order to meet consumer demand for ’77 F-body vehicles, the facility and its workers were asked for 50 percent more output with a model-year startup rate of 504 units per day. That grew to an astounding 672 units as the popularity of ’77 Firebirds and Camaros skyrocketed. Let’s put that in relative terms. Imagine a new Firebird or Camaro rolling past your work station every 50 seconds or so and your given task must be completed in that time!

Product volume and quality were just a few of the many concerns that prompted GM to expand F-body production to include the Van Nuys, California, assembly plant in 1978. That eased the tensions at Norwood, but it left a wake of cars that were hastily assembled and the quality sometimes reflected it. Ill-fitting panels, poor exterior finish, and general sloppiness were common customer complaints of the era. And GM was working to improve that image.

What skews our recollection today is that very few Pontiacs truly remain in the exact condition as when they left the assembly plant. As hobbyists we have grown accustomed to restored examples on which hours were spent ensuring that even the most minute detail was addressed. While very appealing and beautiful in many ways, our beloved Pontiacs weren’t always as perfect as we remember them. As with the situation at the overextended Norwood facility, ’77 Firebirds were assembled at a time when function was more of a concern than achieving the level of detail some customers expected.

When HPP was presented the opportunity to photograph a ’77 Trans Am with just 213 miles on its odometer, Editor Tom DeMauro hit the road. He spent hours poring over the Firebird, capturing its smallest details. As described by its owners over the years, it has never been repaired or modified in any way — everything is completely original. In other words, it is a ’77 Trans Am that’s been preserved in its factory-fresh state.

As we share many of those details over the course of the next few issues, you’ll find it certainly lives up to its expectations as a great find. It gives clear insight on original appearances and finishes used during the era, but it also lends some visual clues as to just how quickly the assembly line was moving. In this installment, we start with the engine compartment and what it reveals.

The Shaker, redesigned for ’77, was more angular with a pronounced spine down the center, and was shorter than its predecessor, looking rather subtle with the hood closed. Pontiac released a new Shaker in mid-May 1977 with the sides raised to deemphasize the center spine, making the entire unit look larger. The Shaker on this particular Trans Am is the first-design unit.

The “6.6 Litre” decals on this Shaker indicate a code-XA 400ci Pontiac generating 180 hp. (The same decals were used with the 403 Olds, which was required in California or high-altitude counties.) The optional T/A 6.6 mill rated at 200 hp appears very much the same externally, but it’s equipped with chrome valve covers and “T/A 6.6” decals on the Shaker.

Pontiac V-8s produced early in the ’77 model year were painted the same shade of medium metallic blue as all ’75-’76 units. GM began widely using engines from one Division in models of another Division in ’77, and consumers responded with a class-action lawsuit claiming brand deception. GM responded by having all its Divisions’ engines painted “Corporate Blue,” the hue shown here.

Pontiac changed the Firebird’s air-conditioning system for ’77. Previously it used a unit referred to as a Valve-In-Receiver (VIR), which contained multiple internal valves that constantly cycled to maintained system pressure. This system was comprised of many components, and that made it more costly and time-consuming to install. Pontiac eliminated the VIR for ’77, replacing it with an aluminum accumulator that doubled as a receiver and drier. System pressure was maintained by an orifice tube and a pressure switch to cycle the compressor, the routing and location of each is visible here. Reducing the number of components not only saved weight and improved long-term reliability, it also eased installation.

Small details of most engines are lost or degraded by a combination of age, heating and cooling cycles, and general wear. Because engines of this era were laden with myriad hoses and sensors that controlled specific functions of the emissions system, Pontiac used vacuum hoses with color-coded stripes to denote which components it connected for ease of assembly and service work. The manufacturers’ information is stamped on each hose in the same color as the appropriate stripe.

The large “N” written in black marker on one flap of the carburetor’s secondary air valve is likely an inspector’s mark indicating the unit is ready for installation. It’s easy to see its flange on the intake manifold — as well as that of the EGR — were fitted with some sort of mask intended to keep paint off the machined surfaces during engine assembly, and this bare area certainly rusted immediately. The small disc just to the right of the EGR valve is its transducer, an item that usually goes missing over the years.

Red and green wires running across the intake manifold are part of the wiring harness that controls the A/C. It’s not difficult to see the common area where the wires were grouped together and routed just above the No. 2 intake runner. On most cars today, the tape is usually missing and the wires run in most any direction. It’s now easy to understand why. Despite only 213 miles on the odometer and the engine not being subjected to countless heating and cooling cycles, this tape is still barely hanging on.

The code-XA 180hp 400 is fed by a No. 17057274 Rochester Quadrajet. An identification tag was used to quickly identify the carburetors on the assembly line, and it’s clearly visible on the secondary barrel of the main body. The throttle cable retains its original paper tag that was used by assembly line workers to identify the proper cable. A pair of return springs in the appropriate shade of semi-gloss black ensures the carburetor throttle blades are completely closed at idle.

A piece often missing is the vent tube gasket, which seals the carburetor to the lower air cleaner assembly. Constructed of close-cell foam rubber, it usually disintegrates with heat and/or age. Another unique piece seen on other low-mile ’77 Trans Ams is the thick airhorn gasket. We’re accustomed to seeing the replacement gaskets, which are quite thin. This original unit is layered and appears to measure about 1⁄4-inch-thick.

Certainly not brought on by routine oil changes is the lack of paint surrounding the oil filler cap, which is also engine color. Possibly oil or grease prevented proper adhesion, or since the filler cap was already installed when the engine was painted, the paint may have cracked upon cap removal and continued to flake off.

Another common trend we’ve noticed when documenting low-mile ’77 Firebirds is the lack of consistency in the point where the air conditioning wire harness crosses over the front of the engine. On some engines it’s forward of the thermostat housing, while on others it’s behind, so either path could be considered correct.

A hotly contested discussion in the hobby is the color of the master cylinder. The unit on this particular Firebird was painted black; rust indicates its machined surfaces were left natural. The gold finish on the power-brake booster appears to be zinc dichromate or cadmium. Visible directly beneath it is the cast-iron combination valve, which was left natural during assembly, as evidenced by the rust. Identification tags on the master-cylinder clamp and brake booster should match the appropriate boxes on the buildsheet, telling workers which units this particular Firebird was to receive during assembly.

Where the four spark plug wires pass over the driver-side valve cover and No. 7 separates off and runs downward, the remaining three then pass through another clip. On this particular Firebird, the open hole is nearest to the carburetor, while on others it’s nearest the master cylinder. It was likely the installer’s choice!

Flat-black paint was applied over the red-oxide primer base on the firewall. Seam sealer was applied quickly and heavily, and the braided engine-ground strap’s contorted appearance also hints of a fast moving line. The black overspray on the windshield-wiper motor is from the dealer-installed undercoat package.

A paper tag on the coil cover of the HEI distributor is for easy identification and installation. Its last four digits (3269) are the same as those of the complete part number, 1003269. The tach lead (single brown wire containing a fusible link) runs parallel to the firewall and approaches the distributor cap from the rear. Note how tightly the spark plug wires are routed in relation to the distributor cap. Spark plug wire loom clips are used to keep them separated to prevent cross arcing.

“E” stamped in black on the alternator case is likely some sort of inspection mark. We see that its fan, pulley, and the retaining nut are all plated in clear zinc and the lower spacer is left natural.

The wires exiting the main engine harness are grouped using a plastic tie, and from the appearance, it looks to have been performed hastily. The wires partially shield the valve-cover-identification tag, which denotes the engine-application code and base-spark-timing setting. Gathered with it is the Shaker drain tube, which happens to be broken off from the Shaker housing.

The hose connecting the air cleaner to the fresh air duct located in the fender is constructed of woven fiber. Usually missing on a well-used car, those that remain are often tattered beyond use. The yellow stamping on the radiator hose contains manufacturer information, as well as an identification code to ensure the correct unit is installed at the time of assembly. In addition to yellow, HPP has documented white stampings on other original cars.

Amazingly, the 400 in this Trans Am retains its original oil filter, which was installed prior to the engine being painted, as evidenced by the surface rust on the block and oil pan that the filter shielded from being completely covered. The black overspray present on the filter and oil-pressure-sending unit is the dealer-installed undercoat. The bolt protruding downward from the boss cast into the automatic transmission case serves no purpose! The hole is not even threaded and the bolt dangles loosely in it. Your guess is as good as ours on this one!

On this T/A, the hood latch is as clean as the day it left the factory. The body appears to be coated in black phosphate, while the latch mechanism is cadmium-plated. A close look at the fasteners that secure it and other pieces to the radiator support reveal that not only are they coated in black phosphate, the manufacturer markings are different, which indicates the assembly plant used various hardware suppliers and matching them was not a priority.

The emissions label contains detailed information about the engine, its spark advance and idle speed settings, and the emissions-control system. Each particular engine had its own label, which can be identified by the two-digit code located in the upper left-hand corner. Code-FA in this instance is for the 400-inch base mill backed by an automatic transmission. This particular label can be difficult to source today, as it isn’t frequently reproduced. Visible just beneath the label is the stamped part number for the radiator support (527654), as well as the day it was produced—February 28, 1977, which is typical for a vehicle built in mid-April. Join us next month as the exploration continues.